JPH0818212B2 - Vacuum suction type rotary work holder - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a rotary work holder mounted on a lens polishing machine to suck and hold a lens of a work by vacuum suction.

[Conventional technology]

Conventionally, as the vacuum suction type rotary work holder,
As shown in the figure, a rotating portion 74 is rotatably attached to the inside of a cylindrical fixed portion 71 having a closed end via bearings 72 and 73. An air introduction path 75 penetrating the axis is formed in the rotating portion 74. A work holder 76 is attached to the lower end of the rotating part 74, and the work 77 can be sucked and held by the work holder 76 via the air introduction path 75. Then, a vacuum suction type rotary work holder that prevents air leakage by interposing a sealing material 79 between the lower end of the air introduction path 78 provided at the closed end of the fixed part 71 and the upper end of the air introduction path 75 of the rotating part 74. Are known.

[Problems to be Solved by the Invention]

However, according to the vacuum suction type rotary work holder in the above-mentioned prior art, the lower end of the sealing material 79 is always the rotating part 74.
Is abutted against the upper end of the rotating part 74, and a frictional drag force is always generated to suppress the rotation of the rotating part 74. This allows the work 77
It becomes difficult to smoothly rotate the work holder 76 that sucks and holds the. As a result, there is a drawback that the shape quality of precision polishing and high-speed polishing cannot be stabilized.

The present invention has been developed in view of the drawbacks of the above-mentioned prior art. A sufficient suction force can be obtained when a workpiece is sucked, and smooth rotation can be obtained by not suppressing the rotation of the rotating portion during polishing. The object is to provide a vacuum suction type rotary work holder.

[Means and Actions for Solving the Problems]

According to the present invention, an air inlet for sucking and discharging a work provided at a closed end of a cylindrical fixed part having a closed end, and a rotary shaft of a rotary part rotatably mounted inside the fixed part. An air introduction path, an air introduction path formed in a gap between the fixed portion and the rotating portion, and a sealing material for opening and closing the upper portion of the air introduction path provided inside the air introduction path in the gap are provided.

1A and 1B are conceptual views of a vacuum suction type rotary work holder according to the present invention.

Reference numeral 1 denotes a cylindrical fixing portion having a closed end 2, and an air introduction port 3 is bored in a shaft center portion of the closing end 2 (hereinafter, referred to as an upper end surface) of the fixing portion 1. A through hole 4 having a diameter larger than that of the air introduction port 3 and communicating with the air introduction port 3 and coaxial with the air introduction port 3 is provided inside the fixed portion 1. Furthermore, the fixed part 1
A lower end surface 5 is provided with a hole 6 communicating with the through hole 4 and coaxial with the through hole 4 and having a larger diameter than the through hole 4.

A substantially convex rotating portion 7 is rotatably fitted in the through hole 4 and the hole 6. The rotating portion 7 is provided with an air introduction passage 8 penetrating its axis, and a holder 10 for sucking and holding the work 9 is formed in the lower portion. A sealing material that does not come into contact with the inner peripheral surface of the hole 6 on the upper outer peripheral surface of the rotating portion 7.
11 is slidably fitted. Further, the inner peripheral surface of the through hole 4, the upper outer peripheral surface of the rotating portion 7, and the inner peripheral surface of the hole 6 and the lower outer peripheral surface of the rotating portion 7 form air introducing passages 12 and 13, respectively.

The vacuum suction type rotary work holder having the above structure sucks and holds the work 9 by vacuum suction 14 from the air inlet 3. At this time, the air in the air introduction path 12 is drawn upward, and the external atmospheric pressure 15 flows into the gap 16 through the air introduction path 13. Due to this inflow, the sealing material 11 moves upward and blocks the air introduction path 12. Therefore, the vacuum suction 14 acts only on the suction of the work 9 through the air introduction passage 8 (see FIG. 1A).

When the work 9 is polished by the polishing tool 17, air is discharged 18 to the air inlet 3. As a result, the air flowing into the air introduction path 12 pushes down the sealing material 11. Therefore, the contact between the fixed portion 1 and the rotating portion 7 is released, and the polishing drag force against the rotating force is not generated. The air discharge 18 does not generate a frictional drag force during rotation during the polishing process even if the air discharge 18 is stopped after the seal material 11 is once separated from the fixed portion 1 (first
(See Figure b).

〔Example〕

Hereinafter, embodiments of the vacuum suction type rotary work holder according to the present invention will be described in detail with reference to the drawings.

(First Embodiment) FIGS. 2A and 2B show a first embodiment of the present invention, and FIG.
FIG. A is a vertical sectional view, and FIG. 2b is a vertical sectional view with a part omitted.

Reference numeral 21 is a cylindrical fixing portion having an upper end surface 22, and an air introduction port 23 is bored in the axial center portion of the upper end surface 22 of the fixing portion 1. A rotating portion 26 is rotatably fitted and held in the fixed portion 21 via bearings 24 and 25. Rotating part 26
The air introduction passage 27 for suction and discharge that penetrates the axis of the
And a work holder 28 is attached to the lower part thereof, so that the work 29 can be sucked and held via the air introduction path 27. A taper step portion 30 is formed in the vicinity of the upper side surface of the rotating portion 26, and a lower step portion 31 is formed below the taper step portion 30. Taper step 30 and lower step 31
A seal member 32 is slidably fitted between the above and. A concave portion 35 is formed by the taper step portion 33 and the lower step portion 34 so that the seal material 32 does not come into contact with the inner peripheral surface of the fixed portion 21. The lower step portion 34 of the fixed portion 21 is sealed by the seal material 32 when the sealing material 32 descends and comes into contact with the lower step portion 31 of the rotating portion 26 and stops.
It is formed so as not to contact with. Further, an air hole 36 is formed on the side surface of the fixed portion 21.

The vacuum suction type rotary work holder having the above structure sucks and holds the work 29 by vacuum suction 37 from the air introduction port 23. At this time, the air in the fixed portion 21 is drawn upward. Along with this, the sealing material 32 moves upward,
The seal member 32 is securely held by the taper step portion 33 formed on the 21 and the taper step portion 30 formed on the rotating portion 26,
The air introduction passage 38 formed by the inner peripheral surface of the fixed portion 21 and the upper outer peripheral surface of the rotating portion 26 is closed, and therefore, a sufficient suction force for the suction / exhaust air introduction passage 27 of the work 29 is ensured. (See FIG. 2a).

When the work 29 is polished, air 39 is discharged to the air inlet 23. As a result, the air flowing into the air introduction passage 38 pushes down the sealing material 32. The sealing material 32 is the rotating part 26.
The lower step 34 of the fixed side 21 is stopped by abutting against the lower step 31 of the
Therefore, the air is discharged from the gap 40, and the fixed portion 21 and the rotating portion 26 are released from mutual contact (see FIG. 2b).

According to this embodiment, since the taper step portions 33 and 30 are provided on both the fixed portion 21 and the rotating portion 26, the rotating portion 26
Even if the fit between the sealing material 32 and the sealing material 32 deteriorates over time, high airtightness can be ensured.

The taper angle formed by each taper step portion 33, 30 is preferably an opening angle of 60 ° to 90 °.

Further, the lower step portion 34 of the fixed portion 21 and the lower step portion 31 of the fixed portion 26.
Are the same position, or the lower step 34 of the fixed portion 21 is in contact with the seal material 32 first, the seal material 32 is fixed.
Therefore, the lower step portions 34 and 31 of the rotating portion 26 and the rotating portion 26 are in mutual contact with each other.

Further, the depth of the recess formed by the tapered step portion 30 and the lower step portion 31 of the rotating portion 26 is 1/3 to 1/1 of the wire diameter of the seal material 32.
2, the depth of the recess 35 formed by the taper step portion 33 and the lower step portion 34 of the fixed portion 21 is 1/2 to 3/5 of the wire diameter of the seal material 32, and the width of the air introduction passage 38 is sealed. If the wire diameter of the material 32 is 1/5 to 1/4 and the length from the taper step 30 to the lower step 31 of the rotating part 26 is set to 4/3 to 2 of the wire diameter of the sealing material 32, The flow is ideal and good sealing material 32 operation is obtained.

Further, it is also possible to configure the sealing material 32 that comes into contact with the rotating portion 26 so as to come into contact with the fixed portion 21. Each dimension setting at that time is realized by reversing the setting values of the rotating unit 26 and the fixed unit 21 described above. However, the type in which the seal member 32 is in contact with the rotating portion 26 has a smaller sliding surface, and thus it is easier to adapt to smooth movement.

Furthermore, by omitting the projection for forming the lower step portion 34 on the inner peripheral surface of the fixed portion 21 and substituting the function of the lower step portion 34 on the upper surface of the thrust bearing 24, The size of the height can be omitted, and the size can be reduced.

In addition, in the present embodiment, the introduction and discharge of outside air are performed through the gap below the fixed portion 21 and through the air hole 36. This air hole
By forming 36, ventilation is further facilitated, the operation of the sealing material 32 is improved, and lubricating oil is also easily injected, so that maintenance work can be performed easily, but the present invention is not limited to this. Alternatively, the air holes 36 can be eliminated.

(Second Embodiment) FIG. 3 is a vertical cross-sectional view showing a second embodiment of a vacuum suction type rotary work holder according to the present invention with a part thereof omitted.

The rotation holding mechanism portion in this embodiment has the same structure as the rotation holding mechanism portion in the first embodiment, and the description of the rotation holding mechanism portion will be omitted.

Reference numeral 41 is a cylindrical fixing portion having an upper end surface 42, and an air introduction port 43 is bored in the axial center portion of the upper end surface 42 of the fixing portion 41. A rotating portion 44 is rotatably fitted and held inside the fixed portion 41. A tapered step portion 45 is formed near the upper portion of the side surface of the rotating portion 44, a lower step portion 46 is formed below the tapered step portion 45, and a recess 47 is formed on the side surface of the rotating portion 44. A seal material (hereinafter referred to as a top) 48 is slidably fitted in the recess 47. On the inner surface of the fixed part 41,
The tapered step 49 is formed so that the 48 does not come into contact with the recess 50.
Are formed.

The top end of the top 48 is fixed to the taper step 45 of the rotating part 44.
The angle formed by the taper step portion 49 of 41 is the same as or slightly smaller than that of the taper step portion 49, and a notch 51 that abuts the lower step portion 46 of the rotating portion 44 is formed in the lower portion.

When the vacuum suction type rotary work holder having the above structure is used, the gap between the concave portion 50 of the fixed portion 41 and the top 48 is b, the gap between the side surface of the fixed portion 44 and the notch 51 of the top 48 is a and the rotary portion. When the gap between the recess 47 of the 44 and the top 48 is c, if this relationship is set to be c <a <b, sliding of the notch 51 of the top 48 by the length d is sufficient for the suction force. And smooth rotation is obtained.

When vacuum suction is performed from the air introduction port 43, the top 48 is pushed up and closes the air introduction path 52. At this time, the top end shape of the top piece 48 is formed at the same angle as or slightly smaller than the angle formed by the taper step portion 45 of the rotating portion 44 and the taper step portion 49 of the fixed portion 41, so that the airtightness is high. Is obtained. Further, by reducing the sliding length d of the top 48, the top 48 can be moved smoothly even with the minimum air pressure.

On the other hand, at the time of processing, the top 48 is pushed down by the exhaust pressure from the air introduction path 52, so that the fixed portion 41 and the rotating portion 44 are brought into non-contact with each other and the rotating portion 44 can be rotated.

According to the present embodiment, by using the top 48, it is possible to realize high airtightness at the time of suction and smooth operation of the sealing material with good response as described above.

(Third Embodiment) FIG. 4 is a vertical cross-sectional view showing a third embodiment of the vacuum suction type rotary wow holder according to the present invention with a part omitted.

The rotation holding mechanism section in this embodiment has the same structure as the rotation holding mechanism section in each of the above-mentioned embodiments, and the description of the rotation holding mechanism section will be omitted.

Reference numeral 53 is a cylindrical fixing portion having an upper end surface 54, and an air introduction port 55 is bored in the axial center portion of the upper end surface 54 of the fixing portion 53. A rotating portion 56 is rotatably fitted and held inside the fixed portion 53. Sealing material on the upper peripheral surface of the rotating shaft 56
57 is slidably fitted. On the sliding surface of the seal material 57, a fluororesin as a lubricant 58 is integrally attached.

A taper step portion 59 is formed on the inner peripheral surface of the fixed portion 53 so that the sealing material 57 does not come into contact with the recessed portion 60. Further, an air hole 61 is formed on the side surface of the fixed portion 53.

The operation of the vacuum suction type rotary work holder having the above structure is the same as that of the first embodiment, and the description of the operation will be omitted.

According to this embodiment, even if the air pressure from the air inlet 55 is small, the smooth movement of the seal material 57 can be easily realized.

In this embodiment, a fluorine-based resin is used as the suitable lubricant 58, but the present invention is not limited to this,
Even if an epoxy resin or metal is used, a sufficient effect can be obtained.

Further, contrary to the present embodiment, it is also preferable to use a lubricant 58 as a sliding sleeve and apply a rubber-based resin to the outer peripheral surface of the sliding sleeve to form a sealing material.

(Fourth Embodiment) FIG. 5 is a vertical cross-sectional view showing a fourth embodiment of the vacuum suction type rotary work holder according to the present invention with a part thereof omitted.

The rotation holding mechanism portion in this embodiment has the same structure as the rotation holding mechanism portion in each of the above embodiments, and the description of the rotation holding mechanism portion will be omitted.

Reference numeral 62 denotes a cylindrical fixing portion having an upper end surface 63, and an air introduction port 64 is formed in the axial center portion of the upper end surface 63 of the fixing portion 62. A step portion 65 is formed near the upper portion of the inner peripheral surface of the fixed portion 62. Inside the fixed part 63, there is an air intake hole in the axial center part.
A rotating portion 67 having 66 formed therein is rotatably fitted and held. In the vicinity of the upper portion of the rotating portion 67, a brim-shaped or sucker-shaped sealing material 68 formed of an elastic material (for example, rubber) is fixed. A notch 69 is formed on the lower end surface of the sealing material 68.

The vacuum suction type rotary work holder configured as described above is provided with a sealing material when suction pressure is generated from the air inlet 64.
Since the outer peripheral part of 68 abuts against and is in close contact with the stepped part 65 of the fixed part 63, the suction pressure from the air introduction port 64 can be connected to the intake hole 66 without being leaked from the gap 70.
Further, since the notch 69 is formed in the sealing material 68, the operation can be made softer and a small suction pressure can be dealt with.

According to the present embodiment, since a force that always tries to restore acts, it is possible to eliminate the contact between the fixed portion 63 and the rotating portion 67 simply by stopping the suction pressure.

〔The invention's effect〕

As described above, according to the vacuum suction type rotary work holder according to the present invention, rotary sliding during polishing of the work is almost eliminated except for the bearing holding the rotary part, and smooth rotation can be realized. At the same time, high airtightness is obtained at the time of adsorbing the work, so that a sufficient vacuum pressure is obtained and the work can be securely adsorbed. This makes it possible to stabilize the shape quality of the lens for precision polishing and high-speed polishing.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1a and 1b are conceptual views of a vacuum suction type rotary work holder according to the present invention, FIGS. 2a and 2b show the same first embodiment, and FIG. 2a is a longitudinal section. Fig. 2b is a vertical sectional view with a part omitted, Fig. 3 is a vertical sectional view with a part omitted, showing the second embodiment, and Fig. 4 is a partial sectional view showing the third embodiment. An omitted vertical sectional view, FIG. 5 is a partially omitted vertical sectional view showing the fourth embodiment, and FIG. 6 is a vertical sectional view showing a conventional example. 1,21,41,53,62 …… Fixing part 2,22,42,54,63 …… Upper end surface 3,23,43,55,64 …… Air inlet 4 …… Through hole 5 …… Lower end surface 6 …… Hole 7,26,44,56,67 …… Rotating part 8,12,13,27,38,52 …… Air introduction path 9,29 …… Workpiece 10 …… Holder 11,32,48,57 , 68 …… Seal material 14 …… Vacuum suction 15 …… External pressure 16,40,70 …… Gap 17 …… Abrasion tool 18,39 …… Air exhaust 24,25 …… Bearing 28 …… Work holder 30,33 , 45,49,59 …… Tapered step 31,34,46 …… Lower step 35,47,50,60 …… Concave 36,61 …… Air hole 37 …… Vacuum suction 51 …… Notch 58 ...... Lubricant 65 …… Step 66 …… Intake hole 69 …… Notch

Claims (1)

[Claims] 1. An air inlet for sucking and discharging a workpiece, which is provided at a closed end of a cylindrical fixed part having a closed end, and a rotary shaft of a rotary part which is rotatably mounted inside the fixed part. An air introduction path, an air introduction path formed in a gap between the fixed part and the rotating part, and a sealing material for opening and closing the upper part of the air introduction path provided inside the air introduction path in the gap. Vacuum suction type rotating work holder.